Rapid and label-free identification of single foodborne pathogens using microfluidic pore sensors

Foodborne pathogenic microorganisms have become major threats that endanger human life and health. The current technology cannot perform rapid screening of foodborne pathogenic bacteria, and fail to timely control food safety risks. Here, we develop a novel microfluidic sensor for real-time and label-free bacteria classification at the single-cell level. Concretely, a low-aspect-ratio SiN micropore with PDMS coating was fabricated, which could significantly reduce the noise of the sensing system, and makes the microfluidic pore sensor sensitive to bacteria discrimination. The prepared SiN micropore equipped with the high temporal-spatial resolution was applied to observe bacterial translocation "events" and the current pulse signals could be obtained, which depend on the size, charge, and morphology of the target bacteria. According to the variation of the current pulse signals produced by different bacteria across the micropore, three common foodborne pathogens such as Salmonella enteric, Listeria monocytogenes, and Escherichia coli were identified. Due to convenience, rapidity, and accuracy, the label-free method we report here has great potential for the identification of diverse foodborne microorganisms at single-cell sensitivity.